This Program Project is comprised of four major research groups supported by three core laboratories. The research emphasis is directed to obtaining information on the molecular biology of serum lipoproteins and their metabolism by various cells and tissues. The four areas of investigation are: 1) Studies on the structure of serum lipoproteins and the interaction of lipids with specific apoproteins, 2) Investigations on the synthesis and degradation of serum lipoproteins and apoproteins by liver, 3) Studies on the regulation of lipid metabolism in cultured cells as influenced by cell/lipoprotein interactions and 4) Studies on the synthesis of lipids by platelets and megakaryocytes. A variety of experimental systems are utilized including whole animals, organ perfusion and cell culture systems. The aim of the studies is to gain insight on the molecular events involved in the metabolism of lipoproteins and the relationship between these events to the development of atherosclerosis.